1. Field of the Invention
The present invention relates to a transfer system, and particularly relates to communication in a transfer system.
2. Description of the Related Art
In performing semiconductor transfer in a clean room or the like, there is a known technique in which an automated warehouse is installed so as to cover loading ports of processing equipment, and is used to relay the transfer of articles between a transfer vehicle and the loading ports (e.g., JP 2001-298069A). FIG. 6 shows a transfer system using the automated warehouse. In this drawing, reference numeral 4 denotes a traveling rail, and 6 denotes an overhead traveling vehicle including a communication unit 7 that communicates with communication terminals 36 arranged above loading ports 12 around the traveling rail 4. Furthermore, reference numeral 8 denotes a processing equipment that processes semiconductor wafers or the like and that is provided with one or a plurality of loading ports 12. Reference numeral 10 denotes the automated warehouse that is provided with a plurality of shelves 16 and an in-warehouse transfer apparatus 18. Articles such as FOUPs 14 are transferred between the overhead traveling vehicle 6 and the shelves 16 of the automated warehouse 10, and are further transferred by the in-warehouse transfer apparatus 18 between the shelves 16 and the loading ports 12.
Before transferring articles to and from the shelves 16 or the loading ports 12, the overhead traveling vehicle 6 has to communicate with a ground-side controller 20 or 22. Thus, the communication terminals 36 are arranged above the loading ports 12 and around the traveling rail 4, and are caused to communicate with the communication unit 7 of the overhead traveling vehicle 6 through optical communication. The communication terminals 36 are provided respectively for the loading ports 12, and respectively for the shelves 16 with respect to which the overhead traveling vehicle 6 may transfer articles. FIG. 6 shows a case in which four loading ports 12 and two shelves 16 are arranged such that the overhead traveling vehicle 6 may transfer articles thereto. Furthermore, since the overhead traveling vehicle 6 does not directly transfer articles to the loading ports 12, a connector 41 is disconnected from the wiring to the controller 20. Moreover, the controller 20 of the processing equipment 8 is connected via connectors 40 and 42 to the controller 22 of the automated warehouse 10. Furthermore, the controller 22 of the automated warehouse 10 is connected via a connector 43 to the communication terminals 36.
Regarding this aspect, the inventor of the present application conducted research concerning the possibility of making the automated warehouse 10 attachable and detachable with respect to the apparatus 8 as shown in FIG. 7. Note that FIG. 7 illustrates results of the research conducted by the inventor, and does not illustrate a known system. When the automated warehouse 10 is detached from the processing equipment 8 as shown in FIG. 7, the connector 42 has to be disconnected, and the connector 41 has to be connected to the controller 20. For this purpose, wiring with a large number of wires has to be performed between the ground side and the ceiling side, and when attaching or detaching the automated warehouse 10, it is necessary to perform switching of the wiring, such as attaching and detaching the connector 41.